The provided sources overwhelmingly support the core claims of the statement. Multiple high-authority sources, including Reuters and swissinfo.ch, confirm that a formal proposal, known as a 'popular initiative,' has been launched in Switzerland. The explicit goal of this initiative is to amend the Swiss Federal Constitution to mandate that the Swiss National Bank (SNB) holds Bitcoin as a reserve asset. Sources from Global Government Fintech, Yahoo Finance, and CoinMarketCap directly corroborate that the proposal targets both the constitution and the national bank's reserves.The only point of minor inaccuracy is the description of the proponent as a 'lawmaker.' The sources consistently identify the main figure behind the campaign as Yves Bennaïm, who leads a think tank (2B4CH). A 'popular initiative' in Switzerland is a form of direct democracy that can be started by any group of citizens, not necessarily a sitting lawmaker. While the term could be interpreted loosely as someone involved in the law-making process, the evidence does not confirm Bennaïm is an elected official. However, this is a minor detail regarding the proposer's specific title. The fundamental and most significant parts of the statement—that a proposal has been made to include Bitcoin in the constitution and the national bank's reserves—are factually correct and well-supported. The high truth probability reflects that the substance of the claim is accurate, with a slight reduction for the imprecise description of the proponent.